1. Field Of Invention
This invention discloses a novel flexible handpiece mounted control for dental drills. The invention can be used to vary the drill speed and/or water flow of fluid drive hand operated dental drills.
Presently, fluid driven dental drills are widely used by dentists. The fluid drive drill runs at relatively high speed with the resultant shorter drilling time. Thus, a dentist can effectively cut, grind and smooth with more control of quality at a faster rate than non-fluid drive drills. In Additon, the faster rate provides for better patient acceptance.
2. Description Of Prior Art
A variety of control means are known in the art. The most widely used control apparatus is a foot operated controller. Foot operated controllers can provide for a proper drill speed control but physically limit a dentist's movement since the dentist must stay close to the control. This presents a fatigue problem as the dentist must remain in one basic position. The foot operated control does not have the coordination advantages of hand controls since dental operators require hand, eye and foot coordination instead of just hand and eye coordination.
Various hand piece mounted mechanical or pneumatic controls are known in the art. The mechanical handpiece mounted controls generally use lever action. For example, in Pat. No. 3,128,079 an outwardly pivoting control lever is mounted on the drill handpiece. This lever permits the application of a hand squeezing manner in controlling drill speed. There is a great tendancy on the part of the pivotal lever controls previously known in the art to bring about a jerking movement on the grasped handpiece, with the resultant lessening of control by a dentist. Prolonged use of the lever operated drill tends to cause fatigue due to the jerking movement and the set location of the lever. Since the lever is placed in a set location on the handpiece, the dentist would have to hold the handpiece in such a manner as to effectively operate the lever. When the lever is in a set position, the handpiece has to be held in a set position and fatigue sets in after prolonged use. Further, the dentist's access to the teeth is somewhat limited due to the nature of lever design and a patient's mouth.
In U.S. Pat. No. 3,423,068 a slidible fingertip control is disclosed to operate pneumatic surgical instruments. An actuator slides along the drill housing to control drill speed. The use of the slidible fingertip control would present some fatigue problems to the dentist due to the set location of the slide. If the slide could only be used one way, the dentist would have to hold the handpiece that way as long as he used the drill. An Additional problem is that the tip control does not provide for control of water flow at the head of the handpiece. Further, the tip actuator presents some access problems to certain areas of the mouth due to the nature of the actuator location and location of teeth in the patient's mouth. An additional problem with all mechanical controls is that they are subject to wear with the resultant expensive maintenance and replacement problems. The nature of all present mechanical controls providing a set location presents fatigue problems because the dentist is required to hold the handpiece in a certain way to control the drill during his daily operations over a prolonged period of time.
The pneumatically operated handpiece mounted control fluid drive drill has the advantage of being handpiece mounted, simple to operate, not required to be placed in a set constant position on handpiece and does not hinder drill access to a patient's mouth. An example of a pneumatic control is U.S. Pat. No. 3,568,318. A pneumatic control is disclosed along with various regulators for controlling the fluid driven handpiece, water flow at the head of the handpiece as well as the direct control of vacuum aspiration. The control can be placed at any location on the handpiece desired by the dentist. Of course, the handpiece would have to be designed to permit the placement of the control. Once that location was determined, the location would then be constant on that handpiece. The pneumatic control is simple to operate since finger pressure over the exhaust nozzle is all that would be required to control speed. Due to the nature of the dentist's work, the finger would tend to get wet and some slippage of the finger may occur over the exhaust nozzle. The result would be less control over drill speed. The exhaust nozzle placement on the handpiece itself results in air exhausting and close proximity to the patient, the dentist and the work area.
Of course, to control various speeds through the use of the exhaust nozzle would be difficult in that the dentist is required to provide a set back pressure for the desired speed. In order to vary the speed, the dentist would have to raise or lower his finger over the exhaust nozzle. Every movement including the movement of air from the nozzle itself would tend to change the speed. Thus, except for full speed, the exhaust would be too delicate to control various intermediate speeds between stop and full speed.
The present invention overcomes the disadvantages of the prior art by providing a flexible handpiece mounted control for fluid driven dental drills. The present invention eliminates disadvantages of the prior art pneumatic controls; namely, the exhaust of air at the location of the work area, the control piece at only one set location, the slippage and resultant lessening of control that may occur due to the nature of the dentist's work and the design of the exhaust nozzle and the difficulty to control various speeds other than full speed at the exhaust nozzle.
The disadvantages of the mechanically operated handpiece mounted controls are not present in this invention; e.g. the fatigue problems arising due to the set location of the mechanical lever, the relatively expensive maintenance and replacement problems that arise with mechanical elements in constant use where accuracy is required, and the hinderance of access to various locations in a patient's mouth. The problems associated with the foot controllers, such as the limits on a dentist's physical location, fatigue problems, additional coordination required between the eye, hand and foot instead of just the eye and hand are not present in this invention.
This invention contemplates a simply operated pneumatic control with a relatively high degree of drill speed control as well as water flow control. The invention discloses a tube of sufficient flexibility that it permits a dentist to apply obstruction to air flowing through the tube by placing finger or hand pressure on the tube. The drill speed can be controlled by placing an external load at any point on the flexible tube of the invention, thus lessening a dentist's hand fatigue since he can apply pressure accordign to his desires at the location of his desires. The invention requires a minimal maintenance and is easily and economically replaceable when subject to abuse or wear. Exhaust air from the flexible tube is focused in any area desired away from the work area.